Process of reducing and shaping bamboo rods



(Nd Model.)

W. N. DURANT & W. H. PRIOHARD.

PROCESS OF REDUCING AND SHAPING BAMBOORODS.

No. 606,623.. Patentedaunezs, 1898.

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PATENT Prion.

WALTER-N. DURANT AND wELLs II. PRICHARD, or MIL AUKEE, Wisconsin.

PROCESS OF REDUCING AND'SHAPlNG BAMBOO RODS."

SPECIFICATION forming part of Letters Patent No. 606,623, dated June 28, 1898.

Application filed January '7, 1897. Serial No. 618,398. (No model.) i

I To a/ZZ whom it 'may concern.-

. have invented new and usefullmprovements in Processes of Reducing and Shaping Bamboo Rod's, of which the following is a specification.

Our invention relates to improvements in processes for reducing and shaping bamboo stalks.

The object of our invention is to provide means for reducing the ends of bamboo stalks to a uniform size and rendering them impervious to moisture in order that the rods can be utilized in the construction .of bicycleframes.

Our invention is further explained by reference to the accompanying drawings, in which Figure 1 represents a longitudinal section of the die used for heating and compressing the bamboo rods, in which is shown a similar section of a piece of bamboo rod compressed therein. Fig. 2 is an end view of the die shown in Fig. 1.

Like parts are referred to by the same reference-letters in both views. r

A represents the conical-shaped walls of the die into which the ends of the bamboo rods to be compressed are forced.

, B represents a section of bamboo as it appears when forced into the die.

0 are fastening-lugs by which the die may be secured to a bench or other stationary support inany obvious manner. The mouth D of the-die is preferably tapered outwardly or enlarged to facilitate entering the ends of the bamboo rod.

Preparatory to compressing or shaping the bamboo rod the die is heated in any convenient manner to a gray heat, when the rod is forced forward into it by the application of pressure. It will be understood that the heat of the mold is quickly'impartedto the hard exterior surface of the bamboo, whereby the same is at once softened, when by the simultaneous application of pressure on the-rod it is readily compressed and caused to enter into and conform in shape to the die.

We are aware that wood has been molded or shaped'by first steaming and then subjecting it to a heavy pressure and that similar results have been attained by subjecting the wood to a dry heat, owing to the presence in the wood fibers of a certain quantity of moisture, which is converted into steam, and owing also to the presence of resin, which melts and aids the steam in softening the tissues. However, the degree of pressure required is very great, and substantially the sameresults maybe obtained by subjecting the wood to a cold compression. In either case the wood is not reduced in size, but is altered in shape while in a softened condition.

In the treatment of bamboo, however, a different method is required, owing to the fact that the interior ofthe bamboo cannot be moistened by steam except at the ends, and there very slowly and to a limited extent, owing to the silicious coating of the fibers and of the exterior surface; neither can the bamboo be compressedwhen cold without disintegratin g the fibers and reducing the stalk to splinters; We have found, however, that by subjecting the stalk to a given degree of heat less than that which would char or burn it that is, to the heat known among metalworkers as a, gray 7 heat-the silicious coating of the fiber cells and of the exterior surface of the stalk is melted sufficiently to become plastic, and as this coating constitutes the cliief strength of the bamboo cells the lat ter can, when so heated, be readily collapsed or pressed together, and the silicious coating will then fill the interstices and solder the fibers together, thus rendering the bamboo absolutely impervious and impenetrable even by strong acids, such as nitric acid, sulfuric acid, &c. So readily and completely do the cell-walls collapse that it is possible forus to reduce the stalks to one-third or even onehalf of their original diameter witha very light pressure, such as that exerted by a common screw-press acting longitudinally of the stalk, or even by hand-pressure exerted to force the stalk longitudinally into a die'having a conically-enlarged or bell-shaped mouth. The stalks when once reduced will permanently retain the shape and size into which they are pressed, and as the silicious matter hardens when cooled the stalks retain their original strength and appearance except as to size and are less liable to splinter than when in their original form.

Having thus described our invention, what we claim as new, and desire to secure by Letters Patent, is

1. The process of reducing the size of bamboo stalks, consistingin subjecting the stalk to a degree of heat suflicient to soften the silicious coating, and simultaneously compressing the stalk to collapse the cell-walls of the fibers, and cause the silicious coating to fill the interstices and solder the fibers t0- gcther, substantially as described.

2. The process for reducing bamboo stalks, consisting in forcing the stalks longitudinally 

